After five years in development, the next generation of Serial Attached SCSI (SAS) is ready to enter the market with a speed of 6 Gbits/s. The new standard, designated SAS-2 by the T10 Technical Committee, will be marketed as 6-Gb/s SAS, according to the SCSI Trade Association (STA).
The SAS–2 specification describes the features and capabilities for 6-Gb/s SAS products and STA defines 6-Gb/s SAS as a required set of features. The T10 Technical Committee is under the direction of the InterNational Committee for Information and Technology Standards (INCITS). The 6-Gb/s SAS standard maintains backward compatibility with 3-Gbit/s SAS, as well as with 1.5-Gbit/s and 3-Gbit/s Serial ATA, allowing these technologies to operate in the same system.
Other features include a standardized expander zone for increased security, expander self-discovery speeds that quicken the device discovery process during power-up, spread-spectrum clocking to reduce electromagnetic interference, and mini-SAS cabling for external cabling. Maximum cable length has been raised to 10 m from 6 m.
“This new generation of SAS provides investment protection by preserving existing SAS and Serial ATA installations, while propelling the market ahead with important new capabilities,” said Harry Mason, director of industry marketing at LSI and president of the STA. “6-Gb/s SAS extends SAS architecture deeper into enterprise storage by doubling transfer rates, improving the scalability of the topology, and increasing overall reliability, availability, and serviceability attributes. These capabilities support the challenges of clustering, scale-out, and storage tiering, including the growing interest in solid state drives (SSDs).”
SCSI Trade Assoc